Rather than give up that great coverage of some of
the early BIG digis, consider simply switching their INPUT
over to a nice QUIET alternate input channel for APRS
such as 144.99 (if avail in your area) where it can
listen for low-power trackers.
Everyone wins:
* The trackers dont have to compete with a 100% saturated channel
* The surrounding lower digi's dont have to hear the QRM from
the big digi and can do their jobs locally MUCH better.
de WB4APR, Bob